What is in the tenancy agreement - can you ask her to leave? That would save you the problem of finding somewhere new but would probably lose you your friend. If you moved out you might salvage something of your relationship. You certainly don't need to put up with it any longer. if she said she would try to improve, it probably wouldn't last long so it's probably time to bring it to an end sooner rather than later. I think neither of you are really suited to sharing but my sympathies lie with you.